Answer: Organ system level
Explanation:
The levels of organisation of a body includes cells, tissues, organs and organ systems. These levels of organization build on each other. Cells make up tissues, tissues make up organs, and organs make up organ systems. Organ system level involves a group of organs that contribute to specific functions in the body. In the case above the level of organisation the scientist is studying is Organ system level because performing that particular tasks ( stated in the question) involves the contribution of more than one organ(requires a group of organs).
